As a conventional flowmeter test system, as disclosed in Patent Literature 1, there is one that tests the accuracy of a test target flowmeter by connecting the test target flowmeter to a circulation path adapted to circulate fuel and flowing a predetermined flow rate of the fluid through the test target flowmeter.
Specifically, the circulation path is connected with a tank for storing the fuel, and on a downstream side of the test target flowmeter and on an upstream side of the tank, a needle valve for flow rate regulation and a reference flowmeter serving as a reference for the test target flowmeter are provided in this order. In addition, between the reference flowmeter and the tank in the circulation path, an electronic balance introduction path for performing flow rate measurement by an electronic balance is connected through a three-way solenoid valve.
Further, in a test using this flowmeter test system, while circulating the fuel through the circulating path, the flow rate of the fuel flowing through the circulation path is regulated by the needle valve, and then the switch to the electronic balance introduction path is made using the three-way solenoid valve. After the switch to the electronic balance introduction path, the flow rate of the fuel having flowed through the test target flowmeter is measured by the reference flowmeter and the electronic balance, and on the basis of measured flow rate values by them, the test target flowmeter is tested.